路桥过渡段路堤加筋现场试验和数值模拟分析

Experimental and numerical simulation analysis on geosynthetic reinforced embankment at bridge approaches

采用土工格栅加筋处理路堤填土可有效解决路堤填土压缩变形过大的问题,从而减小路桥过渡段桥台与路堤的差异沉降以及缓解桥头跳车的现象.通过现场试验对加筋路堤中格栅上、下表面土压力与格栅变形进行了监测分析.采用有限元方法对比分析路堤在加筋与未加筋2种工况下路桥过渡段路堤变形的差异.结果表明:路堤加筋技术在桥台附近减载作用明显,随着距桥台距离的增加,减载作用逐渐减弱;路堤加筋技术有效减小了桥台与路堤的差异沉降.最后,对桩体弹性模量、桩径、筋材抗拉刚度、路堤填土黏聚力和路堤填土内摩擦角进行了参数分析.

Geosynthetic can be used to reinforce the embankment fill so that it can solve problems of excessive compression effectively, thus reduce differential settlements between bridge abutment and embankment and alleviate bump at the approach of the bridge. The stress and deformation of the soil above and below the geosynthetic were measured through the field test. In addition, the differential settlements at the bridge approach under two conditions （embankment with and without geosynthetic reinforcement） were analyzed by finite element method. The results show that load-reduction of the reinforced embankment technique is significant at the vicinity of bridge abutment, while the effect moderates with the distance from the bridge abutment; and the reinforced embankment technique can relieve the differential settlement at the bridge approach effectively. Finally, parametric studies on elastic modulus and diameter of pile, tensile stiffness of geosynthetic, cohesion and friction angle of embankment fill were carried out.